Selective hydrogenation of acetylene on the PdLa@N-doped biochar catalyst surface: the evolution of active sites, catalytic performance, and mechanism

Carbon materials show great potential in catalytic applications, due to their advantages of wide raw material sources, stable chemical properties, and large specific surface area. In this paper, N-doped biochar was prepared from Pennisetum giganteum for supporting PdLa bimetallic nanoparticles to achieve efficient conversion of acetylene. The results showed that the conversion and ethylene selectivity of the Pd0.25La0.25/N-pgBC bimetallic catalyst could reach 100% and 94.2%, respectively. From the characterization results, it could be inferred that the electron transfer from lanthanum to palladium can weaken the ethylene adsorption onto the negatively charged Pd sites and thus improve the selectivity of Pd0.25La0.25/N-pgBC. It is noted that the bimetallic PdLa/N-pgBC catalyst showed strong component dependence, which may be caused by the difference in electronic or geometric modification caused by different metal ratios. This work has shown that the active site separation effect formed by doping inert metals is of great significance to the whole catalytic field.